Slashdot Mirror
Excursions at the Speed of Light
D4C5CE writes "S/F fans can finally find out what you really get to see at relativistic velocity, and tourists are one step closer to "doing Europe in a day" in these amazing Space Time Travel simulations of the Theoretical Astrophysics & Computational Physics department at the Institute for Astronomy and Astrophysics Tübingen. They put you in a driver's seat that both Armstrong the Astronaut and Armstrong the Cyclist would equally enjoy, in simulators built to ride a bike at the speed of light."
I'm presently ingrossed in Brian Greene's new book called "The Fabric of the Cosmos" and does a wonderful job at creating lively understandable analogies while sticking to alot of interesting science. He covers the history and philospophy of how problems involving realtivity, time, and space have evolved - stronly reccomend it...
If religous zealots don't believe in Evolution, then why are they so worried about bird flu?
What about the G forces at the speed of light? Does it just rip peoples skin off?
I like muppets.
I'd be interested to know how expensive this was... Anyways, I would DEFINATELY love to try this.
If history repeats itself, why can't we study the future?
it has always been difficult to me to understand modern physics since they generally aren't so full of 'seeable' stuff like classical physics. this is a dream come true for a computer guy who wants to know more about the rules of the world around him.
He can run through that city faster then that.
Does this mean that the people who travel daily live longer in relitive to everything else?
You have been warned.
What it's like to ride a bike at the speed of light. I'd imagine, then, you would just sit down on the bike, and then get off, since to you, the trip would be instantaneous.
I don't get it... If you were travelling at the speed of light wouldn't you pass through an entire city in milliseconds? or nanoseconds even? How can you see the buildings?
Lightspeed is a simulator for velocities at c and below. Screenshots are available.
Illegal? Samir, This is America.
Gravity is also a theory.
I wonder what a website (and associated server/network tin) looks like when it's Slashdotted at the speed of light?
Contribute to the online videogame encyclopedia: GamerWiki
Reduce the speed of light to 30 kilometres per hour! Then you too can ride at the speed of light!! Easier if you have a motor bike.
It's a Bagel.
Evolution is also a theory. Let the flames begin.
I have seem something similar to this before. Check out:
http://www.anu.edu.au/Physics/Searle/
and
http://www.anu.edu.au/Physics/Savage/TEE/
Look, I've been through Tübingen at the speed of light, and it doesn't look anything like that!
eleven plus two / twelve plus one
All of science is a "theory." Do you think that's air you're breathing now? Or are you a brain in a jar? My theory says the former, but it could be completely and utterly wrong.
The idea, while cool, is not that new (although doing it interactively might be). There's always the Relativistic Raytracer (more movies), which has been available since 1997.
All this does is attempt to simulate the visual distortion that one would perceive when traveling that fast. The videos look like you could be going 100 mph or whatever in terms of speed, but the distortion of the buildings seems to be what they're trying to get across here. The idea that you could have a long enough street lined with similar enough buildings to even perceive this distortion is beyond fantastical, so there doesn't seem to be a whole lot of point to this other than illustrating the notion that there is visual distortion. But I imagine what you would actually see would be much more of a blur.
This has been done before.
And, unfortunately, the simulations of the view while falling into a black hole are really, really wrong.
And most of the alternatives are conjectures.
Scientists use words like chess masters use pawns; saying something's "just a theory" tends to have roughly the same effect on their mental state as kicking the board over.
For the love of God, please learn to spell "ridiculous"!!!
I always understood that distances lying on lines parallel to your path (e.g. the length of a passing storefront) got shorter as you approached c. In the video it looks like the storefronts remain a constant length, or maybe even expand, as the speed increases. Am I missing something?
Those curved buildings are kinda cool, but how long would those buildings even be in your field of vision if you were blasting past them at the speed of light? I don't think your brain would get a chance to process that kind of detail before it blurred into the image from the next microsecond, which would probably be completely different. I'd say it'd all be a messy blur.
Looking backwards would be kinda sweet though, if it didn't blind you immediately.
I was just thinking, light waves might not cause much of a fuss at the speed of light, but what would happen if, say, an elephant moved at the speed of light? I kinda imagine the videos of buildings and such being toppled near atomic bombs, except exponentially stronger.
or maybe that's brown bike shorts.
eww.
There is quite a bit of very convencing physical evidence for both special and general relativity. Here's the first google item returned, but there's lots more out there to read. http://math.ucr.edu/home/baez/physics/Relativity/S R/experiments.html
I've heard that when you're travelling near lightspeed, things behind you (say, 120 degrees from the forward direction) appear to be in front of you. Can anyone give the Relativity for Dummies version of why this happens?
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
We must proceed with caution by ceasing these speed-of-light simulations. The Chinese would surely use them to advance their space-weaponization program.
Why does this troll keep showing up? The Chinese don't have the resources to compete with the US. They've attempted manned space travel several times (even outright copying the Dynasoar design) and every time have had to cut it because of the cost. For now, I wouldn't worry too much about the Chinese one-upping the US on their own technology. Start worrying when they launch an Orion (not bloody likely).
Note that the Chinese space program is completely under the auspices of the Chinese department of war. By contrast, in the USA, NASA is an entirely civilian effort.
This is a GOOD thing. Remember what happened when the space program was under the United States department of war? (Specifically the Air Force?) That's right, some good engineering was done, but we didn't GET anywhere. It wasn't until NASA was formed that the US actually got into the race.
Javascript + Nintendo DSi = DSiCade
G Force is a quality of excelloration not speed. If you could excellorate at half a G you'd eventually achieve the speed of light and feel very little excelloration. There are real problems like the mass and the fact even tiny objects can strike with the force of an atomic blast. Achieving light speed is a kind of sucker bet. As you near the speed of light the energy required to continue to excellorate increases. No source of energy known can overcome it's own mass to reach the speed of light. There was a proposal to build an enitre ship out of bags of hydrogen ice so the mass would be reduced as you excellorated and there'd be little wasted mass. Even then I think it was unlikely to hit better than half the speed of light. Antimatter is a good option but still couldn't overcome the mass energy issue. In normal space it's unlikely that speed of light will ever be achieved let alone passed.
This is what I see when I sprint to an all you can eat buffet after someone else has offered to pay. I have been called many things, but late for dinner is not one of them.
I prefer Ludicrous speed!
Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
Wouldn't the blueshift when traveling at such speeds push everything out the visible spectrum? So you wouldn't actually see anything, you'd just get a nasty dose of Gamma waves... or worse?
common sense: noun
What those who are ignorant of the subject matter think; usually wrong.
if, ignoring science and all that hoohah stuff, you could ride a bike at the speed of light around the place, would there be any need for traffic regulation or do collisions just become so hideously unlikely that it doesnt matter? /ot
Brain(s): 0.0% user, 1.3% system, 0.1% nice, 98.6% idle
I showed my wife the videos cause they were cool, but she got all misty-eyed about seeing Tubingen again, so I'm in for a long night of hearing about how much fun she had at university there. Sigh. Why can't more people appreciate the value of astrophysics for astrophysics' sake?
The world's only surviving livewriter.
Very cool project - the screenshots posted by the parent comment show nicely that the Tübingen Project forgot to adjust the colors - due to the Doppler effect, colors change dramatically.
Under capitalism man exploits man. Under communism it's the other way around.
They are missing the blueshift you would encounter at that speed. However I guess they couldn't be accurate because wouldn't the frequency would shift to far above the ultraviolet quite quickly?
History will be kind to me, for I intend to write it - Sir Winston Churchill
When traveling at the speed of light, would you experience time subjectivly so it would feel as if minutes had passed in seconds? Would you not need some sort of theoretic device / field, that would allow you to stay together and keep your molocules from travelling at different speeds?
"A learning experience is one of those things that says, 'You know that thing you just did? Don't do that.'" - DNA
Something like...
b 2/200px-Atomic_blast.jpg
http://upload.wikimedia.org/wikipedia/en/thumb/b/
There should, I think, have been at least a nod given to George Gamow whose 1947 book, "Mr. Tompkins in Wonderland," attempted to explain relativity and quantum mechanics by putting Mr. Tompkins into situations like this. If I remember correctly, one of the episodes literally did involve his riding a bicycle in a Wonderland in which c was something like twenty miles an hour.
"How to Do Nothing," kids activities, back in print!
To all of you saying "but wouldnt the journey be through in a nanosecond, and your brain couldnt process it in time". THINK! There are two possible explanations:
1. It is all an experiment in rendering the type of optical distortion created by near light speed for the purposes of imagining travel at that speed, and for the sheer hell of it, and thrill of achievement. And the trip through a nice German town is just an approximate illustration in which we have to suspend our disbelief for a moment and enjoy the visual effects that we have never seen accurately portraited before.
or
2. It is a very, very large town. Since we're travelling a 99% light speed, why did you assume we were still on Earth, and not in some freaky alien German-town-mock-up of astronomic proportions? Why do you think there were no PEOPLE?!!!
"They put you in a driver's seat that both Armstrong the Astronaut and Armstrong the Cyclist would equally enjoy"
But what about Armstrong the overly stretchy action figure?
Everyone is entitled to their own opinion. It's just that yours is stupid.
That was your tour. That'll be $1000 please.
Why are you trying to demonize the Chinese? Which government is warmongering?
Besides the misnomer, "G forces" are proportional to acceleration, not velocity.
"doing Europe in a day"
Sounds like a gang bang pr0n movie.
OK, read the article.
The Through the city at the speed of light demo is all very lens-effect-y, but there's no account of colour-shift. As you get faster the approaching wavelengths will shorten (Blue Shift) until you get fast enough that all (normally) visible light shifts up and out of our acuity.
Everything you'd see would be sub-infrared shifted into your spectrum, and this doesn't seem to take that into account.
Wind whipping through your hair, as you cause massive distortions in space-time throughout Tuebingen at the speed of light:20kph! Wheee!
It is pitch black. You are likely to be eaten by a grue.
What happens if you want to turn?
constant speed != zero acceleration
OK, I am going to pick nits. At the speed of light, there isn't much point to turning to see the sights. Due to length contraction, everything except directly in front of or behind you is now visible at a 90 degree angle to your path.
And, due to time dilation, you don't have the ability to decide to turn in your reference frame. Your entire trip at the speed of light must be zero duration in your reference frame to be of finite duration to outside observers.
Of course, if they simulated those two effects, the bike ride wouldn't be very interesting.
It keeps referring to the "speed of light" which itself is not constant -- is a function of the media it travels in.
--
All your speed is belongs to us.
Are hand signals better than using light signals?
I would think that once you travel at the speed of light, you would feel as though you were standing still (since you're now travelling at a constant velocity).
Thank you so very much. This part of near-light-speed motion has always eluded me. Thanks to your mental image, I am finally able to understand this. And I think I'll be able to explain it to others, as well.
(Although I'm sure it helps that I'm well past tipsy as I type this.)
Since it isn't in the Bible, "absolutists" have deemed it a mere "theory" proposed by "scientists" who may not be "right". Besides, apparently Einstein was Jewish and not a Southern Baptist, and you know that the Southern Baptists have God's own word they are right.
That's Newtonian. The relativistic acceleration equations are different. See this FAQ for the correct equations, which will tell you how long (in either proper or inertial time) it would take to reach a given speed, as measured by an inertial observer initially at rest with respect to the body -- with some calculations for 1 g acceleration.
(For instance, to reach 0.77c requires 1 year of subjective time or 1.19 years of objective time; for 0.97c, it's 2 years subjective, 3.75 years objective; for 0.99999999996c it's 12 years subjective, 113,243 years objective.)
C'mon, surely someone else remembers the episode of Carl Sagan's series "Cosmos" where they did the relativistic motor scooter trick? In a small town in Italy, where the speed of light is only 40 km/hr (strictly enforced!) a young man leaves on a tour of the city at relativistic speeds, leaving his friend and younger brother behind. Sagan describes the effects of blue- and red-shifting, the contraction of the cyclist's length, and the dilation of time. It ends with the young man returning to the place he started, just a few minutes (in his frame of reference) after he left. Sadly, he finds all his friends gone, and only his once-younger brother, now an old man, still waiting for him.
I don't know why, but the bittersweet reunion of the two brothers, as well as the story of the late Wolf Vishniac in the "Blues for a Red Planet" episode, both make me cry.
the "running" scene in The Wizard of Speed and Time .
The BAFC, having learned that physics can have psychoactive effects, has announced a new initiative to counter the spread of so-call "light-speed", and the dangerous effects on our children and communities. "It has come to our attention that high relative velocities can distort the senses and impair driving," Arnold. B Toole, Executive Director of the Department of Health and Bodily Function Control (news, links) said. "Accordingly, we're partnering with the Department of Motor Vehicles and NASA to control this emerging danger."
I forget what 8 was for.
I recall seeing still shots of a speed-of-light visualization in a brochure from Carnegie-Mellon's supercomputing center, back in the early '90s.
I can't find the brochure online (this was pre-WWW), but I think the stills came from this paper, from 1990.
Not that I think that this sort of thing is redundant. As technology advances, this is the type of visualization that's worth repeating on new hardware and new software.
k.
"In spite of everything, I still believe that people are really good at heart." - Anne Frank
Cherenkov light is sort of an example of that. It is caused by particles travelling faster than the speed of light in water. That's not faster than C, since C is just the speed of light in a vacuum.
Pssh. What a waste of time. Just turn on your inertial dampers.
kurzweil_freak
5th Kyu Genbukan Ninpo/KJJR student
Be the darkness that allows the light to shine.
There isn't any law of relativity that says "an object in acceleration always has a slower clock than an object in an inertial state".
That being said: there is a competition between a clock in orbit running slower than a ground clock due to its speed, and running faster due to it being in weaker gravity (gravitational time dilation). For the GPS clocks, those shifts are 7,200 ns/day and 45,900 n/s day, respectively, so the latter wins out, and the clocks run faster. See this page.
Your sig. sir, is as terrible as your sarcasm.
The website looks like a blank white page with the text "Connecting to foo.bar.com" underneath. As for the server, rumor it is under that conditions it changes phase and becomes liquid.
You spelled "were" wrong.
For people really wanting to see how it would look to travel at the speed of light, you could always try the open source 3d space simulator Celestia.
I find that watching planets whiz by as you travel at the speed of light is pretty entertaining. I've had some fun just trying to steer with a joystick at this speed.
Of course, I suppose if you really were going this speed (or even 99.9% of it), you'd see some wierd spectral shifting (or that circular blur effect as in the article's animation), which is not shown by celestia.
What you're talking about (the slowing down of light in glass, etc.) is the effect of light hitting a molecule of something, being absorbed by it, and then being reemitted out the other end.
Light's speed is a constant, c. It's the speed of absorbtion and reemission that changes it's apparent speed through substances.
I [may] disapprove of what you say, but I will defend to the death your right to say it.
So if mass increases as speed increases wouldn't some of your bodily processes start to take on some rather bizarre side effects.
Imagine your heart trying to pump blood which has tripled in mass per unit volume. Also might be advisable to visit the white throne before doing any excursions near light speed. Can you imagine having to... well... you know after several mass multiplications.
Haha, I was thinking the same thing...quite awesome that old B-movie sci-fi shows using cheap lens effects to convey speed had it right all along.
I looked at the front page, and I saw an article about OSS Java, that was posted a week ago!!!
/., I can read stories before they are even submitted!
Wow!! the effects of time/spped of light being made clear!
Now I don't need to subscribe the
#hostfile 0.0.0.0 primidi.com 0.0.0.0 www.primidi.com 0.0.0.0 radio.weblogs.com
Okay, let me try..."Creationism is a religious myth. Intelligent Design is based on that religious myth. Let the flames begin."
I stated a fact, but I just don't feel that will be enough to start a flame war. What do you think?
Authority questions you. Return the favor.
If you're going to misspell a word, don't make it the one you emphasize in ALL CAPS...
Ydco co
Salvia Divinorum. :)
Insane stuff.
I wouldn't recommend it
someone at the university of hannover made a simmilar thing/ stone1.htm
http://www.itp.uni-hannover.de/~dragon/stonehenge
in german though..
To many big words for me...
Especially on a Monday Morning...ugh
Your skill in reading has increased by one point!
Surely it would be intensely dark, as you are travelling at the same speed as the photons that would enter your eye.
After a brief period the photons that you hit, but which couldnt bounce off any faster than you are already going would build up over your front, acting as a shield for further photons getting into your eyeball (assuming you hadnt been pulverised by billions of photons each with a really small amount of momentum hitting you).
NASA didn't get anything done until the Russians started doing things. I think the US Air Force would have gotten there - they did pretty good with breaking the sound barrier.
I remember a document which tried to say there was a link btwn the X15 and the Shuttle. Nah. IMO, if the Airforce had a carried on, they would of built a reusable space-craft.
Patriotism is a virtue of the vicious
Stretch Armstrong? But his arms stretch out to next week!
You have two hands and one brain, so always code twice as much as you think!
Normally we use the words absorbtion and re-emission to refer to electron energy-level transitions within the molecule: photons are absorbed and promote electrons to higher energy levels; then, at a somewhat random time and in a somewhat random direction (not uniformly), electrons drop to lower energy levels and re-emit photons. (Note that these transitions aren't instantaneous, nor entirely well defined in time, but we call them quantum events anyway).
A notable effect of complete absorbtion and re-emission events is the tendancy to randomise the direction and phase of the radiation.
When slight slows down in a substance, this is different. It's due to coupling between the light and the molecules of the substance. Photons aren't absorbed in the sense of electron energy-level quantum transitions, but rather the passing photon wave packets interact with the electron waves to modify the phase of the photons. You could think of it as fractional absorbtion and re-emission, each molecule affecting the path and phase of each photon only a very small amount.
There is a qualitative difference between the two effects: light slowing down in a substance usually only randomises the phase and direction very slightly.
Here's a daft analogy. Light slowing down is like running through a vast plain of spinning merry-go-rounds, occasionally touching one with your hand or foot so that it affects your motion. Absorbtion and re-emission is like occasionally jumping onto a merry-go-round, waiting for a little with your eyes closed, then jumping off again.
-- Jamie
I'm making one assumption in writing this. I assume that your cyclist never turns his head. This seems like a likely assumption, since, if he does turn his head, there would be no need for relativity to explain why he can see the lamppost after he's past it.
What you're saying is, that a cyclist going at high speed past a lamppost will at some point see a mirror image of the back of the lamppost. This is flat out wrong. Which parts of the lamppost that are seen by the cyclist, does not depend on his speed.
The mental image I get when I read your post, is that of a cyclist, 'seeing' a billiard ball photon being fired from a lamppost - just as he is passing it - curving in across his path so that he runs into it. This is the ether explanation for the constant speed of light, disproved by the Michelson-Morley (sp?) experiment.
In fact, in any inertial system light always behaves the same. The relative speed of the lamppost emitting the photon, does not affect the behavior of the photon in, say, an inertial system where the cyclist is at rest at origo - apart from deciding what frequency it has. He can see it if it is incident upon him within his field of vision, not otherwise.
Objects going past you at relativistic speeds will indeed appear to be rotated. This is because the perspective you get of the closer part of the object becomes mixed with the perspective of the further off part, which is from an earlier time.
Imagine that a rod has two synchronized watches, one in each end. When the rod is some way off, you have a head-on perspective of it; as you go past it, you will see more of its side. Imagine that your eyes are so fast, that you can tell that the further off watch appears to be behind (whether the rod is moving or not), due to the fact, that the image of that watch has farther to travel. At relativistic speeds, you would then see the closer part of the rod curve away from you, since the side perspective, of the closer part of the rod, becomes mixed with the head-on perspective, of the further off part. (Drawing pictures would help at this point.)
However, the constituent perspectives in all this, are still the same that you would see, if you went past at a non-relativistic speed.
Woooo! In the 2nd video it takes 26 seconds to go around the block. My car can drive faster than the speed of light! I'm really glad that I bought the 2.5 liter, because I don't want to go warp speed with the turbo.
Gas mileage, save the whales, ya know.
Jeez, folks, someone was just asking a question...
The speed of light is just c. The familiar equation e = mc^2 is read "e equals em cee SQUARED."
Energy has the dimensions of a mass times the SQUARE of a speed. For example, kinetic energy is 0.5 mv^2. Think of accelerating a car. It takes longer to accelerate from 30 to 60 than it does to accelerate from 0 to 30
"How to Do Nothing," kids activities, back in print!
Your basic assumptions are wrong.
First, it's not a perception only that objects contract in length in the direction of motion (remember, the frame of reference you are observing is always at rest! It's the universe that is moving, not you.) It's an actual contraction. Time dilation is likewise. The reason this must occur is because of the simple fact that the speed of light is the same in ALL frames of reference. This means the particle of light you see is travelling the exact same speed relative to you as the particle of light someone in one of the buildings sees as you zip past them.
There has to be some "give" in the universe to allow this to hold true. That "give" is the actual contraction of size and expansion of time.
The relativity effects are not simple perception distortions; the actual distance shrinks and time dilates. Objects get distorted in reality.
Finally, to you, those particles of light weren't "bending" to get to your eye. They travelled straight from the lamppost (or wherever the lamppost was when the light was bounced off of or emitted from it) to you. You can't see the back of the lamppost.
The radical sect of Islam would either see you dead or "reverted" to Islam.
He knows what he's talking about, unlike the GP.
As a minor nitpick, the USAF was never under the Department of War. The National Security Act of 1947 changed the Department of War into the Department of Defense (well, merged Department of War with the Department of the Navy), and the Army Air Corps into the United States Air Force.
I've always wondered about this. So if you leave Earth and fly around at near the speed of light and come back, more time would have passed on Earth than would for you. But with everything being relative, couldn't you see it that the Earth was flying around at near light speeds in relation to you, while you were standing still? So then why does the time pass slower for you than the other way around?
But with everything being relative, couldn't you see it that the Earth was flying around at near light speeds in relation to you, while you were standing still?
Yes.
So then why does the time pass slower for you than the other way around?
The Earth sees time pass slower for you, and you see time pass slower for the Earth. However, if you go out and come back, everyone will agree that you're younger than people who stayed behind on Earth. Reconciling this is the basis of the twin paradox.
So, in order 99.999999996% the speed of light, it would take you 12 years but, to an independent observer, it would take over 130,000 years? That is the coolest thing I've heard all week (all month for that matter).
(I'm intimately familiar w/relativity, but it's still facinating to hear the concept expressed in such terms.)
Einstein believed until the day he died that the entire universe must be predictable down to its smallest scale, however deep that may lie. He couldn't accept that quantum physics was inherently random, and thought that it was just a matter of making precise enough observations of quantum systems to be able to predict them with certainty.
So, you have a photon. It has no mass, so it always travels at c in a vacuum. Since it travels at c, in its frame of reference the universe has no duration and no length. It is emitted from one atom and absorbed by another instantaneously, from its perspective. Also, the rest of the universe exists outside the photon's light cone (which incidentally, has a zero radius and zero length), so the rest of the universe is therefore completely irrelevant to the photon. Remember also that every frame of reference is perfectly valid.
This means that for every photon that ever has been or will be emitted by one atom and absorbed by another, there is a relativistic frame of reference in which those two atoms are tangent. That means, for example, that if you turn your naked eye on the light from a star 100 light-years away, photons emitted from that distant sun 100 years ago are striking your retina, and for those photons the entire universe is a single point that bridges the star and your eye instantaneously. It must have therefore been "known" 100 years ago when the photon came into being that it would strike your eye, and therefore by extension the entire universe must be completely deterministic.
My head hurts thinking about it.
If by travelling at the speed of light you get anywhere instantly, then how come we assume that what we see in the skies is old news? I mean... I've read that the light from a star which is 10 light years far away from us will take 10 years to reach us.
That means that the image of the star we see in the sky is the one from ten years ago.
Wouldn't all this "travelling at the speed of light gets us anywhere instantaneously" debunk that?
What is it about having a submitted post about something out there, that suddenly makes you realise how obvious it is that the exact converse is true.
If anyone cares, I had a mental picture of a lamppost rapidly going by a still-standing cyclist. Except that, the lamp had blinds that would allow it to shine only in one direction. I drew a line from the cyclist's eyes to the lamp, along the edge of his field of vision, and thought, stupidly, that the blinds would have to be open along this line.
The PP's post was entirely right, and mine was entirely wrong, as far as it was different, though the rest still holds.
http://www.anu.edu.au/Physics/Searle/Obsolete/Rayt racer.html
n load.html
The results are a lot more realistic.
You can even find some nifty animations there:
http://www.anu.edu.au/Physics/Searle/Obsolete/Dow
Greetings
Sven
In doing some reading on Einstein's General Theory, I ran across the idea that Einstein's theory of how time dilates in the presence of an intense gravitational field could be proven by a red-shift in light affected by that gravitational field, the light functioning as a "clock" that would shift its spectrum in direct relationship with the gravitational time distortion.
Fine, I thought. Light does make a pretty reliable and observable clock. So, what does that mean for the Special Theory? Well, for objects moving away from each other, no problem. At relativistic velocities, there would be a red shift, which would fit with Einstein's theory of time dilation. However, since the Special Theory suggests dilation as the only relativistic time distortion caused by high velocity, any blue shift experienced by converging objects is really problematic. Blue-shifted light would indicate a contraction of time, something that the Special Theory doesn't consider at all. But maybe we should.
Do a few thought problems, and it becomes clear that, at least with regard to velocity, time dilation is but one side of a two-sided Doppler coin.
The Special Theory is great, but maybe not the last word, even in dealing with just velocity effects. It doesn't pay much attention to vectors. It hints at but doesn't really address the possibility that, when two objects have a relationship of extreme velocity, what is most distorted by relativistic effects is not either object's length, mass, or passage through time, but each object's ability to use light to "observe" the other, particularly with regard to its location and velocity.
After one hundred years of digesting the Special Theory, we really ought to be doing more than creating more dazzling illustrations of it. It needs correcting and refining, too.
Why don't we mount a video camera on top of a photon? Afterwards we watch the resulting video in complete amusement.
Years ago there was a tv (on the BBC) series in which Peter Ustinov 'explored' Einstein's theories, and blackholes.
For years since I've been trying to find out whether or not anyone else remembers this, or knows where a copy of the series might be found.
Oh yes, and he had a much better film of this effect and it was motorcycle based too!
@peetm